You can use the email form to spam people

[MatthewStanciu]

Related to #40

There are no limits to how many times you can enter someone's email. Anyone can enter any email, and although the person needs to confirm before they're actually added to a list, someone who wants to be a jerk could use the email form to spam someone with 100 "Verify your email" emails.

This website also has no protection from bots, so it's actually really easy for someone to do real damage (and make us hit our email sending limit).

Solution: Keep track of recently-submitted emails and only allow the same email to be inputted every minute or two.